船舶重力的作用中心称为（）。
A．稳心
B．漂心
C．浮心
D．重心
参考答案：D
表示同一种物质的是（ ）
A．银和水银
B．冰和干冰
C．金刚石和石墨
D．苛性钠和烧碱
Recently I bought a beautiful car, ________ was reasonable.
A. of which price the price of whose C. the price of which D. which price
